Abstract：
Quaternary ammonium compounds (QACs) are a class of surfactants commonly used in disinfecting and cleaning products. Their use has substantially increased during the COVID-19 pandemic leading to increasing human exposure. QACs have been associated with hypersensitivity reactions and an increased risk of asthma. This study introduces the first identification, characterization and semi-quantification of QACs in European indoor dust using ion-mobility high-resolution mass spectrometry (IM-HRMS), including the acquisition of collision cross section values (DTCCSN2) for targeted and suspect QACs. A total of 46 indoor dust samples collected in Belgium were analyzed using target and suspect screening. Targeted QACs (n = 21) were detected with detection frequencies ranging between 4.2 and 100 %, while 15 QACs showed detection frequencies > 90 %. Semi-quantified concentrations of individual QACs showed a maximum of 32.23 µg/g with a median ∑QAC concentration of 13.05 µg/g and allowed the calculation of Estimated Daily Intakes for adults and toddlers. Most abundant QACs matched the patterns reported in indoor dust collected in the United States. Suspect screening allowed the identification of 17 additional QACs. A dialkyl dimethyl ammonium compound with mixed chain lengths (C16:C18) was characterized as a major QAC homologue with a maximum semi-quantified concentration of 24.90 µg/g. The high detection frequencies and structural variabilities observed call for more European studies on potential human exposure to these compounds. For all targeted QACs, drift tube IM-HRMS derived collision cross section values (DTCCSN2) are reported. Reference DTCCSN2 values allowed the characterization of CCS-m/z trendlines for each of the targeted QAC classes. Experimental CCS-m/z ratios of suspect QACs were compared with the CCS-m/z trendlines. The alignment between the two datasets served as an additional confirmation of the assigned suspect QACs. The use of the 4bit multiplexing acquisition mode with consecutive high-resolution demultiplexing confirmed the presence of isomers for two of the suspect QACs.
摘要：
季铵化合物(QAC)是一类常用于消毒和清洁产品的表面活性剂。在COVID-19大流行期间，它们的使用大大增加，导致人类暴露增加。QAC与超敏反应和哮喘风险增加有关。这项研究引入了第一个识别，使用离子迁移高分辨率质谱（IM-HRMS）对欧洲室内灰尘中的QAC进行表征和半定量，包括获取目标和可疑QAC的碰撞横截面值(DTCCSN2)。使用目标和可疑筛查对比利时收集的总共46个室内灰尘样品进行了分析。检测到目标QAC（n=21），检测频率范围在4.2％至100％之间，而15个QAC的检测频率>90%。单个QAC的半定量浓度显示最大值为32.23µg/g，中位数∑QAC浓度为13.05µg/g，并允许计算成人和幼儿的估计每日摄入量。最丰富的QAC与美国收集的室内灰尘中报告的模式相匹配。可疑筛查允许识别另外17个QAC。具有混合链长（C16：C18）的二烷基二甲基铵化合物被表征为主要的QAC同系物，最大半定量浓度为24.90µg/g。观察到的高检测频率和结构可变性要求欧洲对人类潜在暴露于这些化合物进行更多研究。对于所有目标QAC，报告了漂移管IM-HRMS得出的碰撞截面值（DTCCSN2）。参考DTCCSN2值允许表征每个目标QAC类别的CCS-m/z趋势线。将可疑QAC的实验CCS-m/z比与CCS-m/z趋势线进行比较。两个数据集之间的对齐作为分配的可疑QAC的额外确认。使用具有连续高分辨率解复用的4位多路复用采集模式确认了两个可疑QAC的异构体的存在。
